Z-Wave to ZigBee Bridge Endpoint?

Abstract thought. ZigBee has binding for direct control and Z-Wave has associations for the same basic functionality. Anyone ran across a device that can do both?

It’s a pretty well known gap that using a Z-Wave switch with ZigBee bulbs is useless without a coordinator platform (like HA). This, probably hypothetical, device would sit on both networks where the switch could be associated to the Z-Wave side and the bulbs (or whatever) bound on the ZigBee side where this made up device would bridge those two (basically a relay).

You seem to be describing a hub with both Zigbee and Z-Wave radios that bridges sensors and actuators across platforms.

Simply put, that is HASS.

The radio modules are physically separate mostly due to the different RF designs and partly due to the approvals process for standards certification - e.g. Z-Wave Alliance.

Whilst it might be technically possible to create simpler hardware and software than a RPi4 running HASSOS, by the time you’ve tried to link Sensor 1 with Actuator 2, you’ve basically created HASS (or openHAB, or similar). You could use the FOSS protocol stacks with some custom code in the middle, but that’s where Paulus started…

The simplest design is to just use one protocol - e.g. Zigbee and Z-Wave devices can talk directly to each other via the same protocol (common example - IKEA Tradfri remote → bulb).

You could of course just use Matter and Thread - which is what the industry is starting to move to. This either makes devices IP addressable from cloud controllers, or gives local control.

Binding and associations are, more or less, point to point links that coexistent with a coordinated network. So no, they are different things.

The use-case here is control in the event that the coordinator platform (HA in this case) is inop. Yes, architecture design changes could fill this void, but not really what I’m asking about.

Local fall-back in case of a dead co-ordinator and dead control plane (HASS)?

That sounds like Z-Wave association groups or Zigbee direct control (e.g. what IKEA does by default).

Again, it seems orders of magnitude simpler to standardise on a single protocol, at least for one unit of control (could be Z-Wave in one room, Zigbee in another).

Personally, my fall back is a hardware wall switch (Fibaro FGB-212 have many issues, but local control works well).